ASPHALT PAVEMENT REJUVENATION. Robert E. Boyer, PhD, PE Consultant Asphalt Pavements

Transcription

1 ASPHALT PAVEMENT REJUVENATION Robert E. Boyer, PhD, PE Consultant Asphalt Pavements

2 Asphalt Pavement Rejuvenation Wilford Hall

3 WPAFB, OH 3

4 WPAFB, OH 4

5 WPAFB, OH 5

6 Proof of the Pudding! 6

7 Asphalt Pavement Rejuvenators Importance of Rejuvenators Understanding Rejuvenators Using Rejuvenators

8 Asphalt Pavement Rejuvenators OVERVIEW - 1 Importance of Rejuvenators Pavement Preservation Economic Benefit

9 Pavement Preservation Techniques Crack Seal Rejuvenator Slurry Seal Micro-Surfacing Ultrathin Bonded Wearing Course Thin HMA Overlay

10 Pavement Condition Index Pavement Preservation Timing Rejuvenator/Fog Seal Slurry Seal Crack Sealing; Micro-Surface; Ultrathin bonded Reflective crack relief system Curve shape determined by quality, traffic, climate, etc. In-place recycling Base stabilization; Rehab 0 Years Timing --- PCI = 70

11 Asphalt Binder Prices Cost History: January 2001 thru January 2012 <$150/Ton: 2002 >$800/Ton: 2008?$700/Ton: 2012

12 Average Cost: HMA In-Place $21/ton to $97 ton past 9 years. AC Cost Impact on HMA & Paving Liq. AC COST ton AC COST lb. Lbs. AC in 1 Ton 6% AC Cost in 1 Ton HMA AC Cost SY 1.5" OL AC Cost Per Lane Mile (11'w) HMA COST PER TON IN-PLACE OL Cost for One Lane Mi. $150 $ $9.00 $0.75 $4,840 $21 $11,012 $200 $ $12.00 $1.00 $6,453 $28 $14,683 $250 $ $15.00 $1.25 $8,066 $35 $18,354 $300 $ $18.00 $1.50 $9,680 $41 $22,025 $350 $ $21.00 $1.75 $11,293 $48 $25,696 $400 $ $24.00 $2.00 $12,906 $55 $29,366 $450 $ $27.00 $2.25 $14,519 $62 $33,037 $500 $ $30.00 $2.50 $16,133 $69 $36,708 $550 $ $33.00 $2.75 $17,746 $76 $40,379 $600 $ $36.00 $3.00 $19,359 $83 $44,050 $650 $ $39.00 $3.25 $20,972 $90 $47,720 $700 $ $42.00 $3.50 $22,586 $97 $51,391 Cost for 1 lane mile - $11K to $51K.

13 The use of Fog Seal Rejuvenators early in a pavement s life then repeated every 4-6 years can greatly extend the life of a pavement.

14 Importance of Rejuvenators Economic Benefit 10 Miles of Rejuvenator FOR 1 Mile of HMA Overlay

15 . Importance of Rejuvenators Miles of HMA Overlay 2 Miles FOR Miles of Rejuvenator 5 Miles 50 Miles 1 Miles 1/2 Mile Economic Benefit 20 Miles 10 Miles 5 Miles

16 What is a REJUVENATOR?

17 Asphalt Pavement Rejuvenators OVERVIEW - 2 Importance of Rejuvenators Understanding Rejuvenators Using Rejuvenators

18 Asphalt Pavement Rejuvenators OVERVIEW - 2 Understanding Rejuvenators Chemical Composition of Asphalt Asphalt Components/Fractions Asphaltenes & Maltenes Fractions Maltenes Classes Relationship: Asphaltenes & Maltenes

19 CHEMICAL COMPOSITION OF From Organic Matter 90-95% C & H - Hydrocarbon Heteroatoms [N, O, S] Trace Metals [Va, Ni, Fe] ASPHALT Molecular Structure - Extremely Complex State of the Practice Separate Components by Solubility

20

21 Asphalt Binder Fractions Asphaltenes (A) - fraction of asphalt insoluble in n-pentane. Bodying agent Maltenes fraction of asphalt material after precipitation of asphaltenes. Four functional classes of Maltenes

22 Asphaltenes Fraction/ Maltenes Functional Classes Fractional General Definition Chemical Significant Component Description ASTM D2006 Reactivity Function A High Molecular Insoluble in Very Low Bodying Asphaltenes Wt. Product n-pentane Agent PC Polar Precipitates with High Peptizer for Polar Compounds Compounds 85% H 2 SO 4 Asphaltenes A 1 Unsat. Resinous Precipitates with High Solvent for 1st Acidiffins Hydrocarbons Concentrated H 2 SO 4 Peptized A A 2 Slightly Unsat. Precipitates with Low Solvent for 2nd Acidiffins Hydrocarbons Fuming H 2 SO 4 Peptized A S Wax - Saturated Nonreactive with Low Gelling Sat. Hydrocarbons Hydrocarbons Fuming H 2 SO 4 Agent

23 Petroleum Asphalt is comprised of two fractional components: ASPHALTENES and MALTENES.

24 ASPHALT FRACTIONAL COMPONENTS TYPICAL ASPHALT BINDER SATURATED HYDROCARBONS 2 ND ACIDIFFINS 1 ST ACIDIFFINS MALTENES POLAR COMPOUNDS ASPHALTENES

25 ASPHALT FRACTIONAL COMPONENTS TYPICAL ASPHALT BINDER SATURATED HYDROCARBONS JELLING AGENT FUNCTION SATURATED HYDROCARBONS 2ND ACIDIFFINS SOLVENT FUNCTION ~UNSATURATED HYDROCARBONS 1 ST ACIDIFFINS MALTENES ACTIVE SOLVENT FUNCTION RESINOUS HYDROCARBONS POLAR COMPOUNDS PEPTIZER HIGHLY ACTIVE RESINS ASPHALTENES FUNCTION AS BODYING AGENT WHEN PEPTIZED UNAGED AGED

26 Aging - Reduction of maltenes begins at the HMA plant due to the extreme heating - Increase in chemical activity

27 Aging continues over pavement life by: Exposure to the UV rays Environment Oxidation Process Stripping Action of Water Traffic Wear

28 AGING OVER PAVEMENT LIFE MALTENES Chemical Activity

29 Understanding Rejuvenators CRITERIA FOR A REJUVENATOR must involve two important phenomena: Must contain Maltenes Fraction, to balance Maltenes to Asphaltenes ratio Must penetrate binder to facilitate for chemical activity [fluxing/absorption]

30 ASPHALT FRACTIONAL COMPONENTS TYPICAL ASPHALT BINDER SATURATED HYDROCARBONS JELLING AGENT FUNCTIO SATURATED HYDROCARBONS 2ND ACIDIFFINS SOLVENT FUNCTION ~UNSATURATED HYDROCARBONS 1 ST ACIDIFFINS MALTENES ACTIVE SOLVENT FUNCTION RESINOUS HYDROCARBONS POLAR COMPOUNDS PEPTIZER HIGHLY ACTIVE RESINS ASPHALTENES FUNCTION AS BODYING AGENT WHEN PEPTIZED UNAGED AGED REJUVENATED

31 Rejuvenator Test Sections

32 Asphalt Pavement Rejuvenators Importance of Rejuvenators Understanding Rejuvenators Using Rejuvenators

33 Asphalt Pavement Rejuvenators OVERVIEW - 3 Using Rejuvenators Pavement Project Candidates Specifications [Material/Performance] Performance versus Skid Resistance Other Requirements [Equipment/ Experience/ Environmental Conditions] Application Rate Relationship: Asphaltenes & Maltenes

34 Using Rejuvenators [Excellent Candidates] Paved Shoulders Residential Streets Residential Streets Urban Paved Collectors Shoulders Rural Roads

35 Using Rejuvenators [Unsuitable Candidates] High speed Roads & Expressways Runways & High Speed Taxi Exits Pavement w/excessive Distress Base and/or Subgrade Failure Structural Distress without Repair: e.g., Alligator Cracking; Shoving

36 Using Rejuvenators [Material Specifications, If Desired] Product Purchase Description

37 Using Rejuvenators [Material Performance, Desired]

38 Using Rejuvenators [Material Performance, CONCERN] Trade-Off between --- Performance»AND Friction Resistance MOST IMPORTANT PRINCIPAL for -- Using Rejuvenators!!!!!

39 Using Rejuvenators [Material Performance, CONCERN]

40 Using Rejuvenators [Equipment]

41 Using Rejuvenators [Construction ] Experience/Certification: # Years/# Projects Successfully Complete Environmental Conditions: Dry Surface Precipitation Forecast: Prohibit, when >0.1-in < 4 hrs. Ambient Temperature: > 40 degrees F

42 Spray Application Rates Rejuvenators gal/sy - Ring Test -Test Patches -Test Strips -DO NOT OVER APPLY

43 Asphalt Pavement Rejuvenators [SUMMARY] Importance of Rejuvenators Understanding Rejuvenators Using Rejuvenators

44 Project Documentation Rejuvenator

45 Lajes Field, Azores

46 Pickett Lajes Field, Azores [1983] Application Rate

47 Pickett Lajes Field, Azores [1983]

48 Thank You Questions?